Processing clamp

ABSTRACT

The invention relates to a processing clamp for machining and/or processing of workpieces with large processing forces, including a clamp body with a first clamp arm and a second clamp arm and at least a tool with a first tool part and a second tool part which are movable relative to each other and define a working region. The first tool part is arranged to be traversable along a vertical tool axis on the first clamp arm to close the working region and the second tool part is arranged on the second clamp arm to form a workpiece abutment for at least one workpiece. The first tool part is adjustable from a starting position into a working position by an adjustment device. An actuating device is provided for applying a high processing power acting along the tool axis to the first tool part after the adjustment into the working position by the adjustment device.

BACKGROUND OF THE INVENTION

The invention relates to a processing clamp having a clamp body with a first and second clamp arm and at least a tool with at least two tool parts which are movable relative to each other and define a working region in which at least the first tool part is arranged to be traversable along a vertical tool axis (WA) on the first clamp arm to close the working region. The second tool part is arranged on the second clamp arm to form a workpiece abutment for at least one workpiece in which the first tool part is adjustable from a starting position into a working position by means of an adjustment device. In the working position, the first tool part or a functional element held on the first tool part either abuts against a workpiece supported on the second tool part or is spaced only a small distance apart therefrom, in which an actuating device is provided for applying a high processing power acting along the tool axis to the first tool part after the adjustment into the working position by means of the adjustment device.

Processing clamps and processing stations for incorporating functional elements such as nuts, bolts and similar connecting elements into workpieces made of sheet metal or sheet steel, in particular by joining followed by crimping, are known both in terms of their setup and their mode of operation.

In particular, German Patent No. DE 103 59 879 B4 discloses a hydraulic processing clamp for incorporating functional elements such as nuts, bolts, etc. into workpieces made of sheet metal or sheet steel, that includes a clamp body with a first and second clamp arm, each of which holds one part, for example, of a two-piece tool. The two tool parts, mounted on the clamp arms which are facing each other, define a working region, in particular a working gap, in which the workpiece to be machined or processed and a functional element are accommodated. To enable joining and crimping of the function element with the workpiece, at least one of the two parts of the tool is designed to be axially movable, namely in the direction of the other opposite facing tool part. Specifically for crimping, the tool part designed to be axially movable comprises a tool pushrod, also known as a plunger. The tool pushrod is axially movable from a starting position into an operating position to close the processing clamp, wherein the working gap can be reduced in such a way that the tool pushrod is supported on the functional element to be incorporated into the workpiece, and this is supported on the workpiece. The pressure generated by a hydraulic pressure cylinder of the hydraulic actuator device is transferred directly to the tool pushrod and the functional element is thereby fixed in the workpiece by a crimping action, and preferably by permanent material deformation, for example of the functional element and/or the workpiece. In the disclosed processing clamp or setting clamp, the adjustment motion of the tool pushrod or plunger onto the workpiece is executed with a large stroke length but with reduced power, and specifically with an adjustment device provided for this purpose, while in the case of an already closed processing clamp, i.e. in the operating position, the actual processing or crimping is effected by the hydraulic actuator device with an extremely short stroke, but with large force. In order to achieve this the processing clamp is designed such that the pressure piston of the pressure cylinder of the hydraulic actuating device is arranged coaxially with the tool plunger, however, in such a way that the adjusted tool pushrod is axially spaced apart from the pressure piston of the pressure cylinder. Via a coupling means which is radially displaceable relative to the axis of the tool plunger, in particular a pressure piece, the gap that is present between the pressure piston of the pressure cylinder and the adjusted tool pushrod in the working position is bypassed, so that during the crimping operation the pressure piston acts on the tool pushrod via this pressure piece and transfers the high processing force generated directly to the tool pushrod. When the tool pushrod has been moved back into the starting position, or with the processing clamp open, the pressure piece is located at the side of the tool pushrod and thereby releases the space required for the tool pushrod to move back into its starting position again.

Disadvantageously, due to the hydraulic pressure cylinder, known hydraulic processing clamps have high maintenance requirements and the actuation force and/or actuation movement thus generated is difficult to precisely control and regulate. Also, due to the hydraulic pressure cylinder that is connected to the tool pushrod along the axis of motion, such hydraulic processing clamps have a high configuration, which in some applications involving confined spaces can lead to collisions with other components.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved processing clamp which, while maintaining the essential advantage of a low overall height, also allows an individually adjustable processing force.

In the context of the invention the term “processing clamp” is understood in particular to mean a device by which workpieces can be machined or processed under the application of large forces, and which for this purpose includes at least two tool parts that are moveable relative to each other forming a working gap, of which at least one tool part can be mechanically actuated and of which a further tool part forms a workpiece abutment or another workpiece element. The processing clamp can also be part of a processing station or processing device.

An essential aspect of the processing clamp, according to the invention, lies in the fact that the actuator device includes a pneumatic or electric drive unit for generating the processing force and for directly transmitting the generated processing force onto the first tool part, or that the actuator device includes a pneumatic, hydraulic or electric drive unit for generating an auxiliary processing force and a force translation mechanism that can be connected to the first tool part in a driving manner and is designed to translate the auxiliary processing force into the processing force and directly transmit this to the first tool part. In particular, by using an electric drive unit according to the invention, in particular a servo motor unit, a much more precise control of the processing motion, namely the working stroke and the processing force, is possible. As a further advantage, by arranging the servo motor unit on the front face, a low overall height of the processing clamp is obtained. Alternatively, the actuating device can be arranged on the side of the processing clamp, in particular in the area of the yoke section of the clamp body, and be connected to the first tool part in a driving manner via a force translation mechanism. This enables an auxiliary processing force reduced by up to 50% to be generated while maintaining a low overall height, in order to generate, due to the deflection and the magnification of this force by means of the force translation mechanism, a processing force comparable to that of a known actuating device. This allows drive units with a lower performance to be used, which are less expensive and have a lower energy consumption.

As a further advantage, in the working position, the actuating device, including a pneumatic or electric drive unit, can be connected to the first tool part via a force transmission element which is radially displaceable relative to the tool axis, namely by incorporating the force transmission element into a free space extending along the tool axis between the actuating device and the first tool part.

In an alternative embodiment, the actuating device can move along the tool axis jointly with the first tool part and be designed such that it can be fixed on the first clamp arm in the working position. This eliminates the need to provide a force transmission element.

In a further advantageous embodiment, the auxiliary processing force generated by the actuating device is oriented radially to the tool axis or in the opposite direction to the processing force, wherein the force translation mechanism is designed for translating the auxiliary processing force provided by the actuating device into a processing force oriented along the tool axis and acting in the direction of the first tool part

In a preferred embodiment, the force translation mechanism is also designed to magnify the auxiliary processing force provided by the actuating device.

The force transmission mechanism can have different designs, in particular this can be a lever mechanism, a toggle lever mechanism or a wedge mechanism.

Advantageously, the first and second clamp arm are connected together via a clamp yoke section, wherein the actuating device comprising a pneumatic, hydraulic or electric drive unit is arranged in the area of the clamp yoke section on the side of the clamp body and the associated force transmission mechanism is arranged in the area of the first clamp arm.

The first tool part is preferably designed as a tool pushrod or plunger.

As a further advantage, the adjustment device comprises a pneumatic, hydraulic or electric drive unit by means of which an adjustment motion of the first tool part is generated. This ensures that the adjustment device is configured to generate an adjustment motion of the first tool part with high stroke length, but only low adjustment force.

The terms “approximate”, “substantially” or “approximately” in the context of the invention mean deviations from each exact value by +/−10%, preferably by +/−5% and/or deviations in the form of variations which are insignificant to the functionality.

BRIEF DESCRIPTION OF THE DRAWINGS

Further developments, advantages and application possibilities of the invention also arise from the following description of exemplary embodiments and from the drawings. All features described and/or depicted in principle form the subject matter of the invention either alone or in any combination, regardless of how they are drawn up in the claims or by reference thereto. The content of the claims is also considered part of the description.

Hereafter the invention is explained in more detail by means of exemplary embodiments illustrated in the figures.

FIG. 1 is a schematic side view of a processing clamp with a first embodiment of an actuating device according to the invention;

FIG. 2 is a schematic side view of a processing clamp with a second embodiment of an actuating device according to the invention; and

FIGS. 3a-c are schematic functional diagrams relating to different embodiments of a force translation mechanism.

DETAILED DESCRIPTION OF THE INVENTION

The invention is directed to a processing or placement clamp 1. In contrast to the prior art however, the processing clamp 1 according to the invention does not have a direct hydraulic actuating device.

The processing or placement clamp 1, shown only schematically by way of example in FIGS. 1 and 2, is used for incorporating functional or connection elements, for example nuts, bolts, or the like, by joining and/or crimping them into workpieces made of sheet metal, and/or for connecting workpieces manufactured from sheet metal by means of clinching.

To this end, the processing clamp 1 comprises a preferably C-shaped or U-shaped clamp body 2 with a first and second clamp arm 2.1, 2.2 that are connected to each other via a clamp yoke section 2.3. The clamp body 2 is preferably configured as a single piece or a single part.

The processing clamp 1 can also be part of a workstation not shown in the drawings, wherein the processing clamp 1 forms, for example, the manual workstation therein. For this purpose, the clamp body 2 with its clamp yoke section 2.3 can be fixed, for example, on a machine frame not shown in the drawings or on a holder, also not shown. Appropriate holding and connection means are indicated in FIGS. 1 and 2 on the clamp yoke section 2.3 by way of example.

In addition, the processing clamp 1 has a multi-part tool 3 that comprises at least a first tool part 3.1 and a second tool part 3.2, wherein the at least two tool parts 3.1, 3.2 are designed to be moveable relative to each other and define a working region, preferably a working gap AB.

The first tool part 3.1 is arranged such that it can be traversed along a vertical tool axis WA on the first clamp arm 2.1 to close the working region AB and the second tool part 3.2 is arranged on the second clamp arm 2.2 to form a workpiece abutment for at least one workpiece, wherein the first tool part 3.1 is adjustable by means of an adjustment device 4 and an adjustment motion generated thereby from a starting position AU into a working position AR and vice versa. The adjustment device 4 can be designed as an electrical, pneumatic or hydraulic adjustment device which produces an adjustable stroke length that substantially corresponds to the path from the starting position AU to the working position AP along the tool axis WA.

In the working position AR the first tool part 3.1 or a functional element held on the first tool part 3.1 either rests against a workpiece supported on the workpiece abutment or on the second tool part 3.2, or is spaced only a small distance apart therefrom. The first tool part 3.1 is designed for example as a punching-head style crimping tool, which is only shown schematically in FIGS. 1 and 2. Such a punching-head style crimping tool can be designed, for example, in the form of a tool pushrod or a so-called plunger, which can be guided displaceably along the tool axis WA in a housing mounted on the first clamp arm 2.1 for an axial adjustment stroke. As the second tool part 3.2, a matrix-like tool part is provided, for example. It is the interaction of the two tool parts 3.1, 3.2 that affects the joining and crimping of the respective component(s) in the workpiece.

The adjustment device 4 causes an adjustment motion of the first tool part 3.1 with a large adjustment stroke, but with only low adjustment force. The size of the adjustment force is dimensioned in this case in such a way that it ensures the execution of an adjustment movement with corresponding adjustment stroke of the first tool part 3.1 with the functional element accommodated thereon, which means that this is at least equal to the weight of the first tool part 3.1 and of the functional element. In order to transmit the adjustment motion generated by the adjustment device 4, the first tool part 3.1 can have a gearing system, in which a pinion of the adjustment device 4 engages. For this purpose the adjustment device 4 is mounted on the first clamp arm 2.1.

To crimp the functional element however, a processing movement of the first tool part 3.1 with a small working stroke but with high processing force is required, following the adjustment motion with large adjustment stroke, which movement is generated by an actuating device 5, 7 for applying a high processing force F acting along the tool axis WA to the first tool part 3.1 after the adjustment into the working position AR by means of the adjustment device 4. The adjustment stroke therefore exceeds the working stroke by several times.

In accordance with the invention, the actuating device 5 is formed by a pneumatic or electric drive unit for generating the processing force F and for directly transmitting the processing force F generated onto the first tool part 3.1. The actuating device 5, 6 is directly connected in a driving manner to the first tool part 3.1, where appropriate also by means of an additional force transmission element 6. The actuation device 5 is joined to the first tool part 3.1 along the tool axis WA and is fixed to the first clamp arm 2.1. The actuating device 5 generates a processing motion oriented along the tool axis WA, with a low working stroke length but with a high processing force F.

For example, the actuating device 5 can be moved jointly with the first tool part 3.1 and locked to the first clamp arm 2.1 on completion of the adjustment motion, in order then to interact with the first tool part 3.1 without a force transmission element 6.

Also, the actuating unit 5 can be rigidly mounted on the clamp arm 2.1 and the distance produced by the adjustment movement or the adjustment stroke between the actuating device 5 and the first tool part 3.1 can be bridged by means of a preferably passive force transmission element 6, which element comes to rest directly on the aforementioned elements. For this purpose the force transmission element 6 is designed to be radially displaceable with respect to the tool axis WA, which is introduced between the first tool part 3.1 located in the working position AR and the actuating device 5, in order to ensure a direct transmission of the processing stroke with the associated processing force onto the first tool part 3.1.

Alternatively, the actuating device 7 is designed as a pneumatic, hydraulic or electric drive unit for generating an auxiliary processing force HF and a force transmission mechanism 8 that can be connected to the first tool part 3.1 in a driving manner, which is configured to translate the auxiliary processing force HF into the processing force F and transmit this onto the first tool part 3.1. The auxiliary processing force HF generated by the actuating device 7 is oriented either parallel to the tool axis WA or perpendicular to, preferably radially to the tool axis WA, and by means of the force translation mechanism 8 is converted into the required processing movement which acts along the tool axis WA in the direction of the first tool part 3.1, and, if necessary, amplified.

For this purpose the force translation mechanism 8 can have different modes of operation, examples of which are shown in FIGS. 3a to 3 c.

In the embodiment according to FIG. 3 a, the force translation mechanism 8 comprises a lever mechanism which is designed to amplify the auxiliary processing force HF generated by the actuating device 7, wherein the processing force F generated by the force translation mechanism 8 from the auxiliary processing force HF is oriented opposite to said processing force F.

In a further embodiment in accordance with FIG. 3 b, the force translation mechanism 8 is implemented as a wedge mechanism, which is designed for generating a force transmission by means of a wedge effect. For this purpose the wedge mechanism comprises at least two mechanism parts which abut each other over a contact surface extending in an inclined plane, wherein the inclined plane extends slopingly to the tool axis WA. This causes the auxiliary processing force HF acting radially to the tool axis WA to be converted into the processing force F acting along the tool axis WA in the direction of the first tool part 3.1, or processing direction. Also, with an appropriate design of the wedge mechanism an amplification of the auxiliary processing force HF can be effected.

Finally, in the embodiment according to FIG. 3 c, the force translation mechanism 8 comprises a toggle lever mechanism, by means of which the auxiliary processing force HF acting radially to the tool axis WA is also converted into the processing force F acting along the tool axis WA in the direction of the first tool part 3.1, or processing direction.

Alternatively, an alternative suitable force translation mechanism 8 can also be provided, which is configured to perform a corresponding translation of the auxiliary processing force HF into the processing force F and transmitting this onto the first tool part 3.1 and if appropriate, generates an additional force amplification effect.

The invention has been described above based on exemplary embodiments. It is understood that numerous changes and modifications are possible without departing from the inventive idea underlying the invention.

LIST OF REFERENCE NUMERALS

-   1 processing clamp -   2 clamp body -   2.1 first clamp arm -   2.2 second clamp arm -   2.3 clamp yoke section -   3 tool -   3.1 first tool part -   3.2 second tool part -   4 adjustment device -   5 actuating device -   6 force transmission element -   7 actuating device -   8 force translation mechanism -   AB working region -   AR working position -   AU starting position -   F processing force -   HF auxiliary processing force -   WA tool axis 

What is claimed is:
 1. A processing clamp for machining and/or processing of workpieces with large processing forces (F), comprising: a clamp body with a first clamp arm and second clamp arm and at least a tool with at least a first tool part and a second tool part, the first tool part and the second tool part are movable relative to each other and define a working region, in which at least the first tool part is arranged to be traversable along a vertical tool axis on the first clamp arm to close the working region, and the second tool part is arranged on the second clamp arm to form a workpiece abutment for at least one workpiece, in which the first tool part is adjustable from a starting position into a working position by an adjustment device, wherein in the working position the first tool part or a functional element held on the first tool part either abuts against the at least one workpiece supported on the second tool part or is spaced only a small distance apart therefrom, in which an actuating device is provided for applying a processing force acting along the vertical tool axis to the first tool part after an adjustment into the working position by the adjustment device, wherein the actuating device comprises a pneumatic or electric drive unit for generating the processing force and for directly transmitting a generated processing force onto the first tool part, or that the actuating device comprises a pneumatic, hydraulic or electric drive unit for generating an auxiliary processing force and a force translation mechanism that translates the auxiliary processing force into the processing force and directly transmits the processing force onto the first tool part.
 2. The processing clamp according to claim 1, wherein in the working position the actuating device comprises a pneumatic or electric drive unit connected to the first tool part via a force transmission element which is radially displaceable relative to the vertical tool axis, by introducing the force transmission element into a free space extending along the tool axis, between the actuating unit and the first tool part.
 3. The processing clamp according to claim 1, wherein the actuating device is moved jointly with the first tool part along the vertical tool axis and is fixed on the first clamp arm in the working position.
 4. The processing clamp according to claim 1, wherein the auxiliary processing force generated by the actuating device is oriented radially to the vertical tool axis or in an opposite direction to the processing force.
 5. The processing clamp according to claim 4, wherein the force translation mechanism for translating the auxiliary processing force provided by the actuating device into a processing force is oriented along the vertical tool axis and acts in a direction of the first tool part.
 6. The processing clamp according to claim 5, wherein the force translation mechanism amplifies the auxiliary processing force provided by the actuating device.
 7. The processing clamp according to claim 5, wherein the force translation mechanism comprises a lever.
 8. The processing clamp according to claim 5, wherein the force translation mechanism comprises a toggle lever.
 9. The processing clamp according to claim 5, wherein the force translation mechanism comprises a wedge.
 10. The processing clamp according to claim 1, wherein the first clamp arm and the second clamp arm are connected to each other via a clamp yoke section.
 11. The processing clamp according to claim 10, wherein the actuating device comprises a pneumatic, hydraulic or electric drive unit arranged in an area of the clamp yoke section on a side of the clamp body and the force translation mechanism is arranged in an area of the first clamp arm.
 12. The processing clamp according to claim 1, wherein the first tool part is a tool pushrod or plunger.
 13. The processing clamp according to claim 1, wherein the adjustment device comprises a pneumatic, hydraulic or electric drive unit.
 14. The processing clamp according to claim 1, wherein adjustment device generates an adjustment movement of the first tool part with a large adjustment stroke length, but only a small adjustment force. 